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Collagen SDS-PAGE - (Aug/25/2006 )

Hello - I just run an SDS-PAGE on a collagen I mixture. At what MW should I expect the single strands to appear and where should the triple helices? Is it reasonable to expect triple helices after adding DTT and boiling at 95 C ? Thank you!

-salamander-

QUOTE (salamander @ Aug 25 2006, 09:07 AM)
Hello - I just run an SDS-PAGE on a collagen I mixture. At what MW should I expect the single strands to appear and where should the triple helices? Is it reasonable to expect triple helices after adding DTT and boiling at 95 C ? Thank you!


Well, where you expect the monomer strands, depends on the type of collagen, for instance type II consists of 3 identcal a-chains, type I however has 2 similar chains and 1 lower. I you have not found it yet, I can sent you a website where you can find all the molecular weights (I'm not at my work now)
You can also expect dimers and trimers (dimer 2 a-chains and trimer has all 3). Certain cross-links in the collagen are impossible to get rid of, even after the dtt and boiling, so you will always have the di- and trimers if you are not working with recombinant collagen. Recombinant collagen can be produced in monomers.
If you want to know more about this, you can always contact me, collagen is my thesis subject smile.gif

-aspergillie-

Hi,
I came across your response to another researcher asking questions on collagen SDS PAGE separation. Same topic as I'm interested in and researching on at the moment. Since you are doing your thesis on this I have a few questions for you. I'm using collagen III (from calf skin- SIGMA) and have run SDS-PAGE with beta-mercaptoethanol/boiling treatment before loading of samples. Native collagen III shows me three bands, and from what I understand regarding your reply below, the highest band should be trimeric form collagen, the middle one dimeric form and lowest one (which runs just below the middle one in my case - 15% running gel) to monomeric form, which from the literature are denoted respectively, gamma, beta and alpha and should correspond respectively to about 340 KDa, 170 KDa and 97 KDa. Do you confirm this? Thanks for any help you can give.



QUOTE (aspergillie @ Aug 29 2006, 02:47 PM)
QUOTE (salamander @ Aug 25 2006, 09:07 AM)

Hello - I just run an SDS-PAGE on a collagen I mixture. At what MW should I expect the single strands to appear and where should the triple helices? Is it reasonable to expect triple helices after adding DTT and boiling at 95 C ? Thank you!


Well, where you expect the monomer strands, depends on the type of collagen, for instance type II consists of 3 identcal a-chains, type I however has 2 similar chains and 1 lower. I you have not found it yet, I can sent you a website where you can find all the molecular weights (I'm not at my work now)
You can also expect dimers and trimers (dimer 2 a-chains and trimer has all 3). Certain cross-links in the collagen are impossible to get rid of, even after the dtt and boiling, so you will always have the di- and trimers if you are not working with recombinant collagen. Recombinant collagen can be produced in monomers.
If you want to know more about this, you can always contact me, collagen is my thesis subject smile.gif

-LIZ65-

QUOTE (LIZ65 @ Nov 7 2006, 09:38 AM)
Hi,
I came across your response to another researcher asking questions on collagen SDS PAGE separation. Same topic as I'm interested in and researching on at the moment. Since you are doing your thesis on this I have a few questions for you. I'm using collagen III (from calf skin- SIGMA) and have run SDS-PAGE with beta-mercaptoethanol/boiling treatment before loading of samples. Native collagen III shows me three bands, and from what I understand regarding your reply below, the highest band should be trimeric form collagen, the middle one dimeric form and lowest one (which runs just below the middle one in my case - 15% running gel) to monomeric form, which from the literature are denoted respectively, gamma, beta and alpha and should correspond respectively to about 340 KDa, 170 KDa and 97 KDa. Do you confirm this? Thanks for any help you can give.


I can confirm this, only I thought that the alpha-chains of collagen type III were 139 kDa (in human).
For collagen type III it is possible to see a shift between reduced and unreduced boiling.
And I use 4-8% tris-acetate gels from Nupage (invitrogen), you can get a really good seperation of the three fragments (I think this nice separation is only possible with gradient gels).

-aspergillie-